How do I link libcurl to my c++ program in linux?

You can try to use curl-config --libs.

Your header file inclusions are just fine; your problem is occurring at the linking step. In order to link against libcurl, you need to add the -lcurl command line option, assuming it's installed in a standard directory:

g++ -o sms ./src/sms.o -lcurl

If it's not installed in a standard directory, you also need to add the -L/path/to/libcurl, e.g. something like:

# Assuming that /home/geekman/workspace/libcurl is where libcurl.a is located
g++ -o sms ./src/sms.o -L/home/geekman/workspace/libcurl -lcurl

Also note that the -lcurl option has to appear after the list of object files you're linking, otherwise it won't link properly.

Anyone who is using ecplise CDT then you need to do following. First on terminal enter

curl-config --libs

On my machine, the result is

-L/usr/lib/i386-linux-gnu -lcurl

then do according to this screenshot and you will be able to compile. btw don't forget to add header files in your code

So you enter library folder path without -L and library name without -l because they will be automatically added by linker.

An alternate answer (the first one is excellent). Consider using the output returned by "pkg-config --libs libcurl" as an argument to your compiler.

For example,

CPPFLAGS=`pkg-config --libs libcurl`

g++ $CPPFLAGS myfile.o

Pkg-config is a standard way for open source libraries to communicate to you how to link against them / #include their files.